Nanoparticles used to create topical Viagra rival
People taking erectile dysfunction (ED) medications such as Viagra (sildenafil citrate) and Cialis (tadalafil) can experience side effects including headaches, facial flushing and indigestion.
Research presented at the 104th Annual Scientific Meeting of the American Urological Association (AUA) suggests that topical application of a nanoparticle formulation could be effective and reduce side effects.
The formulation consists of hydrogel and glass nanoparticle platform that is capable of sustained release of nitric oxide (NO), a compound that can aid ED by relaxing smooth muscle cells and expanding blood vessels so they fill with blood.
Currently the treatment is in preclinical testing but has shown effectiveness in rats. The drug delivery formulation could also be applied to other ailments that would benefit from topical administration.
Ira Sharlip, an AUA spokesman, said: "This is a very interesting concept which has potential to impact treatment of many conditions including erectile dysfunction if it can be translated from the animal lab to clinical practice.
"It remains to be seen whether the effect of the nanoparticle technology is a local or a systemic effect."
Details of the research
The researchers investigated the effectiveness of the formulation by applying it the penis skin of seven rats and measuring the erectile response by intracorporal pressure/blood pressure (ICP/BP) ratio.
Of the seven rats that had the formulation five experienced a positive change in the ICP/BP ratio and had visible erections. The average time for erectile response was 65 minutes.
Sizeable market opportunities
The 2005 market for ED drugs was valued at $1.95bn by Datamonitor and this is predicted to grow because of the ageing population, rising obesity and lessening of the social taboo.
This represents a sizeable market for companies such as Pfizer and Eli Lilly and extending the life-cycle of their products will increasingly become a priority when generic competition approaches.
Consequently alternative drug delivery technologies that can provide benefits such as lower doses and reduced side effects could become attractive in the coming years.
